Groupon is the target of a boycott protest by anti-porn group Morality in Media, which wants the daily deal company to stop selling discounted coupons for walking tours of Kink.com, a porn studio that owns the historic San Francisco Armory building.

The Groupon expires in January 2013. It offers "$28 for Armory and Adult-Film Set Tour for Two at SF Armory (Up to $60 Value)." Here's what buyers get: "Employees lead 60-minute tours for guests aged 18 & older through five floors of historic armory & elaborate adult-film sets."

The armory is a 200,000 square foot reproduction Moorish Castle that has been used a National Guard facility and a film set (parts of Star Wars were filmed there).

MIM wants to stop the Groupon tours because Kink offers movies of men and women being “bound, whipped, objectified and humiliated. They are immobilized, caged and humiliated as objects.” The group also claims that Groupon buyers will witness a "live filming" of a Kink.com movie, although the Groupon itself doesn't promise that.